The present invention relates to a jig for mounting an oil seal in a machine housing. More particularly, the invention is concerned with a jig for mounting an oil seal, capable of automatically preventing, without fail, the oil seal from being fitted in a wrong orientation.
Oil seals are used in machines having a rotary shaft extending through a hole formed in the wall of the machine housing, so as to form an oil-tight seal between the outer peripheral surface of the shaft and the inner peripheral surface of the hole while allowing the shaft to rotate with minimized friction. As will be explained later with reference to the accompanying drawings, the oil seal is unidirectional and has a predetermined orientation. Thus, the oil seal cannot perform its function unless it is mounted in the right orientation. As a matter of fact, however, it is often experienced that the oil seal is mounted in the wrong orientation to cause various troubles, even when the user has paid a specific attention to ensure the right orientation. This problem is serious particularly in the mass-production of the machine employing a manual work for mounting the oil seal, because the mounting of the oil seal in the wrong orientation is inevitable even by the greatest attention paid by the workers. On the other hand, a too much attention in this manual work undesirably lowers the efficiency of the work.